Adsorption Mechanism and Electronic Characteristics of TiO2 and (TiO2)2 Nanoparticles Doped GaNNT for SOF2, SO2F2, and SO2 Detection and Scavenging

Insulation faults in sulfur hexafluoride (SF6-based high-voltage insulation equipment are accompanied by SF6 decomposition; hence, electrical equipment insulation condition monitoring is vital. The first principles calculations are used to investigate the adsorption and electronic characteristics of titanium dioxide (TiO
$_{{2}}{)}$
-gallium nitride nanotube (GaNNT) and (TiO
$_{{2}}{)}_{{2}}$
-GaNNT. TiO2 and (TiO
$_{{2}}{)}_{{2}}$
are first applied for the adsorption of SF6 decomposition species (SO2F2, SOF2, and SO
$_{{2}}{)}$
with the most stable structures binding energies of −10.077 and −10.663 eV, respectively. Through comparing the adsorption energy and electronic characteristics of SO2F2, SOF2, and SO2 on TiO2-GaNNT and (TiO
$_{{2}}{)}_{{2}}$
-GaNNT, these results indicate that TiO2-GaNNT and (TiO
$_{{2}}{)}_{{2}}$
-GaNNT are appropriate sensing materials for SF6 decomposition products. Furthermore, (TiO
$_{{2}}{)}_{{2}}$
-GaNNT has good desorption recovery time (1.527 s) for SOF2 at a specific temperature, and the mode of physical adsorption offers a prominent basis for its desorption as a gas sensor. The results demonstrate that TiO2 and (TiO
$_{{2}}{)}_{{2}}$
can be employed as a novel gas sensitive material for SF6 decomposition species detection, scavenging, and diagnosis in the insulation faults of SF6-based electrical equipment.